Note: If 'rbd' is listed as one of the supported formats, no further
action is required; otherwise proceed to the next step.

If the eucalyptus-node service is running,
terminate/stop all instances. After all instances are terminated,
stop the eucalyptus-node service.

systemctl stop eucalyptus-node.service

Prepare the RHEV qemu packages:

If this NC is a RHEL system and the RHEV subscription to qemu
packages is available, consult the RHEV package procedure to install the
qemu-kvm-ev and qemu-img-ev packages. Blacklist the RHEV packages in the
Eucalyptus repository to
ensure that packages from the RHEV repository are installed.

If this NC is a RHEL system and RHEV subscription to qemu
packages is unavailable, Eucalyptus built and maintained qemu-rhev
packages may be used. These packages are available in the same yum
repository as other Eucalyptus packages. Note that using Eucalyptus
built RHEV packages voids the original RHEL support for the qemu
packages.

If this NC is a non-RHEL (CentOS) system, Eucalyptus-built and
maintained qemu-rhev packages may be used. These packages are available
in the same yum repository as other Eucalyptus packages.

If you are not using the RHEV package procedure to install the
qemu-kvm-ev and qemu-img-ev packages,
install Eucalyptus-built RHEV packages:
qemu-kvm-ev and qemu-img-ev, which can be
found in the same yum repository as other Eucalyptus packages.